Sham Group

Shpyrko Group

Sinha Group

Magnetic films and nanostructures; oxide interfaces and multiferroics

We are using polarized neutron reflectivity and resonant magnetic x-ray scattering to study the details of the depth dependence of the magnetization and the lateral domain structure in the vicinity of the interfaces in compound magnetic structures. The systems being studied include ferromagnetic films deposited on antiferromagnets (so-called "exchange-bias" systems), multilayers exhibiting the giant magnetoresistance (GMR) effect or spin-valve systems, ferromagnet/semiconductor interfaces (so-called "spin injection systems"), magnetic nanodot arrays deposited on solid substrates, and hole arrays in magnetic films.

We are also using resonant magnetic x-ray scattering with coherent x-rays to observe magnetic "speckle" from spin systems, and we plan to study slow dynamics of domain walls in ordered magnetic structures and in frustrated spin systems such as spin glasses, etc. We are also planning to use resonant magnetic scattering with coherent X-rays to carry out imaging of magnetic domain structures in magnetic films using phase retrieval methods , or so-called "diffraction imaging". Eventually, we plan to carry out these experiments at the LCLS free-electron laser X-ray source at SLAC.